Finding AGB Star Phases: Modeling S-Process in a Helium Shell Burning Region

In summary, the conversation discussed the topic of modeling the s-process in a star's Helium shell burning region and the variation of neutron exposure. The individual has consulted three textbooks for information on the topic and is currently in need of sources for the duration of the AGB (asymptotic giant branch) phase. They have found a range of 20-100,000 years on Wikipedia but would prefer more reliable sources. The individual also mentions the importance of citing sources correctly and expresses their interest in physics.
  • #1
malawi_glenn
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Hi!

I have a project where I am supposed to model the s-process in a star in its Helium shell burning region, and i shall do this for a variation of neutron exposure, where neutron exposure are defined as:

[tex] \tau = N* \Delta t [/tex] , t is time. N is number density of neutrons.

So I in principle have calculated everything i need, but what is left is that i don't know the times for different mass of stars where they are in the AGB (asymptotic giant branch), it is in the AGB phase where stars have Helium shell burning outside a C and O burning core. So i must find the time duration of those phases.

I have consulted three textbooks. One is Nuclear Physics of stars by Iliadis, one is Stellar structure and evolution by Prianlik, and one is Modern astrophysics by Caroll.
 
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  • #2
Carroll! :grumpy:

Malawi, I noticed you misspelling the name of Chandrasekhar in another post today, and I hope you will take this to heart: it's not enough to cite your source, you must also spell the authors' names correctly. And if there is more than one, you should not simply omit the other authors! For example, you should cite the book you probably meant as "Bradley W. Carroll and Dale A. Ostlie, An Introduction to Modern Astrophysics, 2nd ed, Addison-Wesley, 2007".

Hope you take this in the spirit suggested--- sounds like you are seriously interested in physics and if so learning to cite properly is part of what you need to learn.
 
  • #3
Now i was just asking if anyone has a suggestion for duration time of AGB phase. When writing reports and so on I am very skilled at citing my sources correctly, I promise you.

But writing in a forum like these, I can feel more freeley. And what other astrophysics book have similar name to "Modern astrophysics by Caroll", there is no doubt what sources I have consulted.

Now I have found on wikipedia that AGB lasts for 20 -100 000years, so now I can calculate some ranges for the Neutron exposure. But I really want better sources, so if anyone has it/know it , please contact me. Otherwise I must go through half the city just to get to my astronomy library and search through a lot of books, and the weather in sweden is kinda sucky now =/
 

1. What is an AGB star?

An AGB (Asymptotic Giant Branch) star is a type of evolved star that has exhausted its core hydrogen and helium fuel. It is in a late stage of its life and is characterized by its large size and low surface temperature.

2. What is the S-process?

The S-process (slow neutron-capture process) is a nucleosynthesis process that occurs in the helium-burning shell of AGB stars. It involves the capture of slow-moving neutrons by atomic nuclei, resulting in the production of heavier elements.

3. How do scientists model the S-process in a helium shell burning region?

Scientists use computer simulations and models to study the S-process in AGB stars. These models take into account the physical conditions, such as temperature and density, in the helium shell and the nuclear reactions that occur during the S-process.

4. What is the significance of studying the S-process in AGB stars?

The S-process plays a crucial role in the production of elements heavier than iron, including many essential elements for life. Understanding the S-process in AGB stars can provide insights into the origin and distribution of these elements in the universe.

5. How does the presence of the S-process affect the evolution of AGB stars?

The S-process has a significant impact on the chemical composition and structure of AGB stars. It can cause changes in the star's surface composition and influence the formation of planetary nebulae and white dwarfs at the end of the star's life.

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